Benghazi returning as big headache for Obama

There's been a lot of smoke in the would-be scandal over the Benghazi attacks, but no real fire yet.

But that may change when three "whistle-blowers" give what Republicans expect to be explosive testimony this week before Rep. Darrell Issa's House Oversight Committee. The controversy over the September 11, 2012 attack on the U.S. consulate and CIA annex in the Libyan city has smoldered, mainly on the right, but the testimony will likely push it back into the mainstream and could be an enormous distraction for an already injured second-term Obama.

Unlike the vast majority of the new information brought forward by the conservative media since the attack, the three whistle-blowers seem credible. One, Gregory Hicks, was the number-two State Department official in Libya before the attack and has decades of experience in the Foreign Service. Another, Eric Nordstrom, was the regional security officer in country for State. And the third, Mark Thompson, is the deputy coordinator for operations in the department's counterterrorism bureau and was involved in Washington's response to the Libya attacks.